Emulsifiable oil composition



United States Patent 3,201,349 EMULSIFEABLE 01L COMPGSETION Richard L.Qnanstrom, Chicago Heights, 11., assignor, by mesne assignments, toSinclair Research, Inc, New York, N.Y., a corporation of Delaware NoDrawing. Filed Nov. 18, 1960, Ser. No. 70,140 2 Claims. (Cl. 252-334)This invention relates to novel soluble oil compositions having rustinhibiting properties. More particularly this invention pertains tonovel petroleum based emulsifiable oils exhibiting excellent rustinhibiting properties as a result of the addition of a combination ofcertain corrosion inhibiting additives.

Soluble oils are used as cutting, spraying and rust preventing oils andgenerally include a small amount of water, an emulsifying agent and acorrosion and rust inhibitor. Although an important function of cuttingfluids is cooling, the prevention of corrosion to both the workingmaterial and the tool has become another important consideration as aresult of the increased use of cast iron and low carbon steels.Emulsifiable cutting oils which are satisfactory for use with alloysteels frequently lack sufficient rust-inhibiting properties forsatisfactory use w-ith cast iron or low carbon steels. The fortificationof a soluble oil with rust inhibitors is complicated not only by thesolubility and compatibility of the inhibitors with the neat solubleoil, but also by the relatively high degree of toxicity of many of theother- Wise acceptable rust inhibiting additivesl It is an object ofthis invention to provide a cutting and grinding fluid containing aparticularly effective combination of materials to inhibit corrosion andrust. Another object of this invention is to provide a cutting andgrinding fluid having excellent cooling and lubricating properties.Still another object of this invention is to provide a non-volatile,toxicologically acceptable, aqueous cutting and grinding fluid that canbe used with cast iron or low carbon steels.

According to the invention, these desirable objectives are attained bynovel soluble oils, which contain a base of mineral lubricating oil andone or more emulsifiers and complexing agents. I supplement the basecomposition with combinations of the following three rust inhibitors:

A. An alcohol amine having the structural formula:

wherein R is a divalent aliphatic hydrocarbon radical containing about 1to 4 carbon atoms, R is R or H, n is 0 to 1 and when n is 0, H0 is H.Compounds of this type include, for instance, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl propanediol, Z-amino- Z-methyl propanol-l,Z-amino-Z-ethyl propanol-l and Z-amino propanol.

B. An oil-soluble tertiary amine having the structural formula:

preferably normal chains and unsubstituted. The preferred amine istri-n-butylamine.

C. A nitrite of an alkali metal having an atomic weight of 22 to 40,i.e. potassium and sodium. Sodium nitrite is preferred.

The rust inhibitors are employed inconcentrations and ratios such thatthey exert corrosion inhibiting effects in the cutting oil.

The proportions of the various ingredients used in compositions of thecharacter described above are quite flexible and may be varied accordingto the particular properties desired in the finished product.Ordinarily, however, the soluble oil will include about 40 to weightpercent mineral oil base, about 8 to 20 weight percent (dry basis) of anaromatic sulfonate emulsifier, about 1 to 5 weight percent of thecombination of the three rust inhibitors and a small amount, forinstance, about 1 to 5 weight percent, of water. Other ingredients, forexample, from about 1 to 10% by weight, can be present as secondaryemulsifiers, germicides, coupling agents, etc.

The oils used as a base and major component in the emulsifiable Oils ofthe present invention are the refined mineral lubricating oils.Generally, the oils used are the conventionally refined coastal oils orconventional refined Mid-Continent oils. The oils may be refined byeither acid-treatment or solvent extraction. Acid-treatment is directedprimarilytoward the removal of asphaltic and the more aromaticconstituents from oils in order to improve their stability and reducesludge and'varnish-forming tendencies. Refining by solvent extractionalso removes aromatic and asphaltic constituents from the more desirableparaffinic and naphthenic components of raw oil. stocks. Accordingly, asI use a sulfonate as described later, to get good results, the oil oflubricating viscosity used in the practice of my invention must becapable of dissolving the sulfonate. Although any oil of lubricatingviscosity can be used in the process of my invention I prefer to use asubstantially anhydrous lubricating oil with a viscosity from about 50to 1200 SUS at F., preferably 50'to SUS at 100 F. I get my best resultswith a conventionally refined coastal oil with a viscosity of about 100SUS at 100 F,

As the primary oil-water emulsifier the oil-soluble aromatic sulfonatesare generally used and include the sodium salts of aromatic oil-solublesulfonic acids, such as the oil-soluble sodium soaps of sulfonic acidsderived from petroleum hydrocarbons, as for example the sodium mahoganysulfonates, obtained as a result of treating a mineral lubricating oilfraction or other liquid petroleum hydrocarbon with concentrated orfuming sulfuric acid, or sulfur trioxide, followed by neutralizationthereof with sodium hydroxide or the like. Although their exact generalstructure may vary, it appears that these sulfonates are composed to alarge extent of aromatic hydrocarbons having either one or two aromaticrings per molecule possible with one or more long-chain alkyl groupscontaining from about 8 to 24 or more car- 3 bon atoms attached to thering nuclei. However, other useful aromatic sulfonates are the syntheticaromatic sulfonates prepared from sulfonic acids, e.g., substitutednaphthalenes and benzenes, by the reaction of parafi'in chains of 8 to24 or more carbon atoms with aromatic nuclei which are then sulfonatedwith fuming sulfuric acid followed by neutralization with sodiumhydroxide. To obtain excellent results, I use a sodium mahoganysulfonate obtained from acid treating a coastal lube oil, for example,with a viscosity of about 100 to about 2,000 SUS at 100 F., although Iprefer to use an oil with a viscosity of about 1,200 SUS at 100 F.Moreover, I get my quality sulfonates by treating separately, fractionsof 100, 300, 1,200 and 2,000 SUS at 100 F. acidtreated coastallubricating oils and blending proportions of these fractions to obtain asatisfactory balance of oil and water solubility when the oil is latermixed with large quantities of Water. Since this is a mahoganysulfonate, it is primarily oil-soluble and is usually about a 10 to 60percent concentrate in a mineral oil, for instance, of a lubricating oilbase, which is included as part of a lubricating oil base in mycomposition. It can have an average molecular weight of about 350 to 500although I prefer a range in between about 400 and 500. To get excellentresults, however, I use a sulfonate with an average molecular weight of430 to 450 and in an amount of about 8 percent to percent (dry basis) ina mineral oil.

The corrosion inhibiting additives of the present invention when used inemulsifiable oils exert corrosion inhibiting properties better than anyone, or any two of the three inhibitors at a concentration equal to theconcentration of the three inhibitors. Although any dispersible amountof the corrosion inhibiting ingredients can be used, corrosioninhibiting amounts are generally employed. I prefer to use about 0.5 to3 weight percent of the alkali metal nitrite, about 0.1 to 1 weightpercent of the alcoholic amine and about 0.5 to 3 weight percenttrialkylamine. For optimum quantities, I employ about 1 weight percentof the alkali metal nitrite, about 0.25 weight percent of the alcoholamine and about 1 weight percent of the trialkylamine.

As aforementioned, optional additives, for instance auxiliaryemulsifying agents, corrosion inhibitors and bactericides can also beincluded in my novel composition. When using an auxiliary emulsifier,for example an alkali metal rosinate, up to 10% by weight can be used.Generally about 3 to 6% by Weight is employed. When using a bactericide,I prefer to incorporate tetrachlorophenol; however, any compatiblebactericide can be used, for example, phenylmercuric acetate, silverpropionate, and ortho-phenyl phenol. Moreover, they can be used eitheralone or in combination in an amount of about 0.5 to 1 weight percent.Other agents in small amounts may be present including, for instance,additional corrosion inhibitors.

It may also be desirable to add a coupling agent to improve theemulsifiability of the various components, i.e., they couple the aqueousportion of the compounded neat soluble oil to the continuous oil phaseto give a clear product and also couple the neat oil to diluent Wateradded to provide the emulsified soluble oil suitable for use. Among thewell known coupling agents useable in the composition are the aliphaticalcoholic compounds, particularly aliphatic ether-alcohol compoundscontaining from about 1 to 30 carbon atoms, for instance, diethyleneglycol; the ether complexes of ethyl Cellosolves, Carbitol, and butylCellosolve; the polyether glycols with terminal ether groups; and thepolyoxyalkylene glycols, as Well as ethylene glycol, propylene glycol,etc. One or more of the above coupling agents can be used either aloneor in mixtures and in various amounts generally about 0.5 to 5%,preferably about 1 to 3 weight percent. The alcoholic amine rustinhibitor component of the present invention is also an excellentcoupling agent and it by itself may provide sufiicient coupling actionin the final cutting oil composition.

The viscosity of the final oil produced by the process of my inventionis preferably about 300 to 800 SUS at F. to facilitate handling andstorage thereof; however, the viscosity can be as high as 1200 SUS at100 F. to minimize volatilization.

In use as a component of a soluble oil emulsion, the compositions aredispersed in about 1 to 200 or more parts of water, depending upon theparticular application contemplated. Thus, where the resulting emulsionis to be used as a lubricant for grinding operations, for example, ithas been found that about one part of the oil for each 10 to 30 parts ofWater, and particularly a one to 15 or 20 ratio, produces verysatisfactory results. For use in quenching operations, emulsions formedwith one part of soluble oil per 5 to 18 parts of water have been foundto be very advantageous. As a rolling mill oil, emulsions containing onepart of the composition for each 15 to 30 parts of water effect verydesirable results.

The invention may be described further with reference to the followingspecific examples.

EXAMPLE I 57 parts of acid-treated coastal mineral lubricating oil witha viscosity of 100 SUS at 100 F. is charged into a kettle containing 32parts of sodium mahogany sulfonate with an average molecular weight of450 to 500 in an amount of 12.8 parts on a dry soap basis and themixture heated to a temperature of about ISO- F. 5 weight percent ofpotassium rosinate (87 percent solid, 13 percent water), 1.5 weightpercent of diethylene glycol (corrosion inhibitor-coupling agent), .75weight percent of tetrachlorophenol (bactericide), 0.25 weight percentof 2-amino-2-ethyl-1,3-propanediol, 1.0 weight percent oftri-n-butylamine and 1.0% sodium nitrite in an aqueous solution areblended in at this temperature. The amount of water in the soluble oilis adjusted to 1.50 weight percent. This mixture is agitated using theLightnin mixer for an additional period of 2 hours.

The weight percent of the ingredients in the composition are:

Compos tion: Weight percent Sodium mahogany sulfonate (40% conc. inmineral lube oil) 32.00 Base oil acid-treated Coastal oil (100 SUS at100i F.) 57.00 Potassium rosinate (87% come. in H O) 5.00 Diethyleneglycol 1.50 Tetrachlorophenol 0.75 2-amino-2-ethyl-1,3-propanediol 0.25Sodium nitrite 100 Water* 1 50 Tributylarnine 1 00 Does not includewater of potassium rosinate component.

The composition of this example, designated composition B, was subjectedto a rust test to determine its usefulness as a rust inhibiting cuttingoil. Other corrosion inhibited compositions can be made by replacing the2- amino-Z-ethyl-1,3-propanediol with a like amount of 2- amino-propanolor 2-amino-2-methylpropanol. The rust test procedure employed isdescribed below.

Rust test procedure A Freshly cut, clean, dry cast iron chips are siftedover a 12-mesh wire screen until they are relatively free from fines anddust. Approximately 40 grams of the sifted chips are placed in a clean,dry 100 ml. beaker and a 3 sufficient soluble oil emulsion is added tocover them. The mixture is allowed to stand for 20 minutes with 6 itorwas added, was also tested. The'results of emulsion stability and rusttests run on the samplesin Table I.

TABLE I Composition A B C D E F G H Sodium mahogany sulfonatc, percent32. O 32. 00 Base oil, percent 57.00 57.00 Potassium rosinetc, percent5. 00 5. G0 Diethylene glycol, percent 1. 50 1. 50 Tetrachlorophenol,percent 0. 75 0. 75 2-amino-2ethyl-l,Bpropanediol, percent 0. 45 0. 45Sodium nitrite, percent 1. 80 Water, percent 1. 50v 1. 50 Tributylamine,percent- 0 1. 80 Neat oil appearance Bright Bright Separated Hazy BrightBright Bright Bright Emulsion stability, 16 hours Good Goo Good GoodPoor Good Good Good Rust test: Observed rust 'Eeavy Slight Heavy HeavyHeavy Light Heavy Heavy trace medium stirrmg at -m1nute intervals. Atthe end of this period I claim:

the beaker is covered with a watch glass and is inverted, allowing theemulsion to drain from the chips as freely as possible. The invertedbeaker, chips and watch glass are placed on clean paper towels. Thebeaker-is drawn to the edge of the watch glass (but retaining the chipsinside the beaker) so as to permit continued drainage and thecombination is allowed to stand undisturbed for 48 hours. The beaker isremoved and the chips are observed'for presence of rust. Rust on chipsthat come in contact with the beaker are disregarded. The results arereported as follows:

No rust Trace rust Light rust Medium rust Heavy rust Very heavy rustEmulsion concentrations of one part oil to 20 and 50 parts tap water(125 p.p.rn. hardness as C,, CO were used in evaluating composition A.For purposes of comparison, tests were conducted on 6 variations ofcomposition B to show that none of the inhibitors of the presentinvention alone, or any combination of two of the three rust inhibitorsin a concentration equal to the total weight of the three inhibitors ofthe present invention, will provide rust inhibition equal to thatobtained by the combination of rust inhibiting additives of compositionB. A sample, designated composition A to which no inhib- 1. Anemulsifiable oil composition consisting essentially of a minerallubricating oil base as themajor component, an oil-soluble sodiummahogany sulfonate emulsifier, about 1 to 5 percent water, about 0.5 to3 percent tri-n-butyl amine, about 0.1 to 1 percent 2-amino-2-ethyl-1,3propanediol and about 0.5 to 3 percent of sodium nitrate.

'2. An emulsifiable oil composition consisting essentially of a minerallubricating oil base with a viscosity of about to 150 SUS at F., about 8to 20 percent of sodium mahogany sultonate, about 1 to 3 percent ofethylene glycol, about 3 to 6 percent of potassium rosinate, about 0.1to l weight percent of 2-amino-2- ethyl-1,3-pr0panediol, about 0.5 to 3weight percent of sodium nitrite, about 0.5 to 3 weight percenttri-n-butylamine and about 1 to 5 weight percent water.

References Cited by the Examiner UNITED STATES PATENTS 2,268,608 1/42McNulty et al 252390 X 2,331,469 10/43 Hamilton et a1. 252401 X2,476,554 7/49 Lincoln et al 252-390 X 2,682,523 6/54 Talley et a1.252-495 2,780,598 2/57 Cafcas 25233.4 X

DANIELE. WYMAN, Primary Examiner.

JULIUS GREENWALD, JAMES S. BAILEY,

Examiners.

[ INITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,201,349 August 17, 1965 Richard L. Quanstrom It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 6, line 25, for "nitrate" read nitrite Signed and sealed this29th day of March 1966.

( L) Am:

ERNEST W. SWIDER Attcsting Officer BRENNER Commissioner of Patents

2. AN EMULSIFIABLE OIL COMPOSITION CONSISTING ESSENTIALLY OF A MINERALLUBRICATING OIL BASE WITH A VISCOSITY OF ABOUT 50 TO 150 SUS AT 100*F.,ABOUT 8 TO 20 PERCENT OF SODIUM MAHOGANY SULFONATE, ABOUT 1 TO 3 PERCENTOF ETHYLENE GLYCOL, ABOUT 3 TO 6 PERCENT OF POTASSIUM ROSINATE, ABOUT0.1 TO 1 WEIGHT PERCENT OF 2-AMINO-2ETHYL-1,3-PROPANEDIOL, ABOUT 0.5 TO3 WEIGHT PERCENT OF SODIUM NITRITE, ABOUT 0.5 TO 3 WEIGHT PERCENTTRI-N-BUTYLAMINE AND ABOUT 1 TO 5 WEIGHT PERCENT WTER.